package com.hzj.alg;

import java.util.concurrent.ExecutorService;
import java.util.concurrent.LinkedBlockingDeque;
import java.util.concurrent.ThreadPoolExecutor;

public class test {

    public static void main(String[] args) {
       StringBuffer S = new StringBuffer();
       S.append(1);
       StringBuilder a = new StringBuilder();
       a.append(1);
    }

    }
